Mechanical hammer



April 8 .1924. 3,490,006

R. GOLDSCHMIDT MECHANIC CAL HAMMER Filed May 27. 1921 v Patented Apr. 8,1924.

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RUDOLF GOLDSCHMID'I, OF WEST END, BERLIN, GERMANY, ASSIG-NOR TO DET TEK-NISKE FORSflGSAKTIESELSKAB, OF ORDRUP, CHARLOTTENIQUND, DENMARK, A GOM-PANY OF DENMARK.

MECHANICAL HAMMER.

Application filed May 27, 1921. Serial No. 473,032.

To all whom it may concern:

Be it known that I, RUDOLF GOLDSCHMIDT, a German citizen, residing at 45Linden Allee, West End, Berlin, Germany, have invented new and usefulImprovements in Mechanical Hammers, of which the following is aspecification.

This invention relates to mechanical hammers and has for its object toprovide means for preventing the escape of lubricant from and the entryof impurities into the casing.

According to the present invention the apparatus comprises thecombination of a reciprocated hammer and a closed casing enclosing thehammer so that the hammer strikes the tool through the wall of saidcasing.

In carrying out this invention the wall of the casing struck by thehammer may be suificiently thin to be flexible or it may be in the formof a flexible diaphragm.

In order that the invention may be more clearly understood, referencewill be hereinafter made to the accompanying diagrammatic drawings,whereon Fig. 1 is a sectional elevation of a mechanical hammerillustrating one form of the present invention.

FFig. 2 is a detail view at right angles to Figs. 3 and 4 are sectionalelevations on a smaller scale illustrating a form of me,- chanicalhammer and showing two further modifications of the invention.

Referring to Fig. 1, which represents a mechanical hammer or percussivetool of the type described in my oo-pending patent application, SerialNo. 436,206 filed 10th January 1921, the tool com rises a casing 44adapted to be sup orted y a handle 43. A tup 45 is adapte to reciprocatewithin the casin 44, for which purpose it is formed with lugs 46supporting a driving spindle 47 driven by a c011 sprmg 48 from aflexible shaft 49 connecte to any suitable form of' prime mover ormotor. The spindle 47 carries a :pur wheel 51 drivin a spur wheel 51 1g.2) on a are. el spindle 47 as described in m a oresaid patent aplication. The spin les 47 and 47 are eac fitted with an excentric weight54, the centrifugal action of which causes reciprocation Of the tup 45,A spring 55 is fitted between a collar 56. on the tup 45 and a collar 57on the casing 44.

It will be seen that the tool comprises essentially four parts, namely,a tool 5 (such as a chisel, rivet head sinker or the like),

a casing 44 having a guide 6 for the tool shank 5, a tup 45 whichreciprocates within the casing 44 and imparts its stored energy byimpact to the tool 5, and the driving mechanism 47, 48, 49, 51, 54,which however varies according to the power available, which may beeither centrifugal action as illustrated or it may be compressed air,electrical energy or the like.

Dust, chippings or destructive fluids may obtain access to the interiorof the casing 44 through the space 7 between the guide 6 and tool 5 andthus damage the driving mechanism or interfere with the lubrication.

The lubricant could also escape through the s ace 7. This is aparticular drawback if t e tup and driving mechanism is flooded. withlubricant, that is to say, if the interior of the casing 44 is wholly orpartly filled with lubricant. Experience has shown that, in the usualconstructions, even with a relatively good joint between the tool 5 andthe guide 6, the lubricant is ejected by the blows imparted to the tool.

In order to overcome these drawbacks, the casing according to thepresent invention is enclosed in such a manner that the energy isnevertheless transmitted by the tup to the tool. For this purpose thetup does not act directly upon the tool, but through the medium of onewall of the cas ing which is interposed between the tool and its drivingtup.

In Fig. 1 a bolster 8 in the form of a plug is secured to a transverseflexible diaphragm 9 which is secured by screws, bolts or the like 10 tothe casing 44 so as to form one wall thereof. The diaphragm 9 issufliciently flexible to enable the p ug 8 to transmit the blow from thetup 45 to the tool 5. The flexible diaphra 9 may be made of an suitablemateria such as thin metal, ru ber, leather or the like.

It is not essential that a flexible diaphragm 9 should be provided. Thecasing 44 may itself be so constructed that its lower wall issufliciently thin to act in the manner of a flexible diaphragm.

Fig. 3 illustrates a percussive hand tool in which the tool 5 issupported in a guide 6 depending from the thm lower wall 13 of a casing14 enclosing the tup 15, which in this case is illustrated as controlledby springs 16 and driven by a universally jointed shaft 17 and flexibleshaft 18 from a motor 19.

It will be seen that in this case the lower wall 13 of the casing is ofreduced thickness as compared with the walls of the casin 14 so that thelower Wall 13 forms a flexib e diaphragm to transmit the blow from thetup 15 to the tool 5.

In the further embodiment of my invention illustrated in Fig. 4, thecasing 14 is formed with a lower non-flexible wall 20 which carries theguide 6 and transmits the blow from the tup 15 to the tool 5.

Claims 1. A reciprocatory tool comprising a casing-having an elastic endwall, a tup guided within the casing, mechanism for reciprocating thetup to cause it to strike the central portion only of said end wall anda tool support on the end of the casing for supporting the tool inproximity to said end wall. a

2. A reciprocatory tool comprising a cas ing, a tu guided within thecasing, mechanism or reciprocating the tup, an extension on said casingforming a support for the tool in alinement with the tup, and atransverse elastic diaphragm between the tool and tup for closing saidcasing.

3. A reciprocatory tool comprising a casing, a tup therein, mechanismfor reciprocating the tup, a tool guide for permitting movement of thetool in the direction of movement of the tup and a fluid-tight elasticclosure for the casing between said tup and tool guide.

RUDOLF GOLDSCHMIDT.

